//+---------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1991 - 2000.
//
// File: Xpr.hxx
//
// Contents: Internal expression classes
//
// Classes: CNodeXpr
// CXprPropertyValue
// CXprPropertyRelation
//
// History: 10-Sep-91 KyleP Created
//
// Notes: Implementation for classes defined in this file will be
// found with either the content index or the query engine.
//
//----------------------------------------------------------------------------
#pragma once
#include <strategy.hxx>
// ..\Inc includes:
#include <pvalxpr.hxx>
class CNodeXpr;
class CCI;
//+---------------------------------------------------------------------------
//
// Class: CXpr (xp)
//
// Purpose: Base (internal) expression class.
//
// Interface:
//
// History: 11-Sep-91 KyleP Created.
// 23-Jun-92 MikeHew Added Weighting
// 05-Sep-92 MikeHew Added Serialization
//
// Notes: Restrictions are converted to expressions during
// normalization. Expressions are aware of issues such as
// what indexes can optimize their evaluation and can
// be evaluated with respect to a particular object.
//
// In contrast, restrictions are just a description of an
// expression.
//
// This class is shared with the content index. Some methods
// only make sense for expressions which are capable of being
// evaluated by the content index. Other methods only apply
// to evaluation in the Query engine.
//
//----------------------------------------------------------------------------
class CXpr : public CValueXpr
{
public:
enum NodeType
{
NTAnd,
NTOr,
NTNot,
NTAndNot,
NTVector,
NTScope,
NTProperty,
NTRegex,
NTPropertyValue,
NTNull
};
//
// Construction-related methods
//
inline CXpr( NodeType type, ULONG ulWeight = MAX_QUERY_RANK );
virtual ~CXpr();
virtual CXpr * Clone();
//
// Index-related methods
//
virtual void SelectIndexing( CIndexStrategy & strategy );
virtual BOOL IsMatch( CRetriever & obj );
//
// Match quality methods
//
virtual ULONG HitCount( CRetriever & );
virtual LONG Rank( CRetriever & );
//
// Value-related methods
//
virtual GetValueResult GetValue( CRetriever & obj,
PROPVARIANT * p,
ULONG * pcb );
virtual ULONG ValueType() const;
//
// Node-related methods
//
NodeType NType() const;
virtual BOOL IsLeaf() const;
inline CNodeXpr* CastToNode();
ULONG GetWeight() { return _weight; }
void SetWeight(ULONG wt) { _weight = wt; }
protected:
NodeType _type;
ULONG _weight;
};
DECLARE_SMARTP( Xpr );
//+---------------------------------------------------------------------------
//
// Member: CXpr::NType, public
//
// Returns: Type of expression node
//
// History: 27-Sep-91 BartoszM Created.
//
//----------------------------------------------------------------------------
inline CXpr::NodeType CXpr::NType() const
{
return _type;
}
//+---------------------------------------------------------------------------
//
// Member: CXpr::CastToNode, public
//
// Synopsis: "Safe" cast down to CNodeXpr
//
// Requires: Type to be one of CNodeXpr types
//
// History: 27-Sep-91 BartoszM Created.
//
//----------------------------------------------------------------------------
inline CNodeXpr* CXpr::CastToNode()
{
Assert ( _type == NTAnd ||
_type == NTOr ||
_type == NTAndNot ||
_type == NTVector );
return (CNodeXpr*) this;
}
//+---------------------------------------------------------------------------
//
// Member: CXpr::~CXpr, public
//
// Synopsis: Destroys an expression.
//
// History: 23-Sep-91 KyleP Created.
//
//----------------------------------------------------------------------------
inline CXpr::~CXpr()
{}
inline void CXpr::SelectIndexing( CIndexStrategy & strategy )
{
strategy.SetUnknownBounds();
}
//+---------------------------------------------------------------------------
//
// Class: CNodeXpr
//
// Purpose: Node with child expressions (Boolean, Phrase, etc...)
//
// Interface:
//
// History: 11-Sep-91 BartoszM Created.
// 05-Sep-92 MikeHew Added Serialization
//
// Notes: CNodeXpr does not guarantee the position of nodes across
// calls to RemoveChild.
//
//----------------------------------------------------------------------------
class CNodeXpr : public CXpr
{
public:
CNodeXpr( CXpr::NodeType type, unsigned cInit = 2 );
CNodeXpr( CNodeXpr & nxpr );
virtual ~CNodeXpr();
virtual CXpr * Clone();
//
// Index-related methods
//
virtual void SelectIndexing( CIndexStrategy & strategy );
virtual BOOL IsMatch( CRetriever & obj );
//
// Match quality methods
//
virtual ULONG HitCount( CRetriever & );
virtual LONG Rank( CRetriever & );
//
// Node-specific methods
//
BOOL IsLeaf() const;
void AddChild ( CXpr* child );
inline void SetChild ( CXpr* child, unsigned iPos );
inline CXpr* GetChild ( unsigned iPos );
CXpr* RemoveChild ( unsigned iPos );
unsigned Count() { return _cXpr; }
private:
unsigned _size;
unsigned _cXpr;
CXpr * * _aXpr;
};
//+---------------------------------------------------------------------------
//
// Class: CVectorXpr
//
// Purpose: Extended from node expression to support weighted vectors.
//
// History: 24-Jul-92 KyleP Created.
// 05-Sep-92 MikeHew Added Serialization
//
//----------------------------------------------------------------------------
class CVectorXpr : public CNodeXpr
{
public:
CVectorXpr( unsigned cInit, ULONG RankMethod );
inline ULONG GetRankMethod() { return( _ulRankMethod ); }
private:
ULONG _ulRankMethod;
};
//+-------------------------------------------------------------------------
//
// Class: CXprPropertyRelation (pv)
//
// Purpose: Performs relational operations on properties
//
// Interface:
//
// History: 11-Oct-91 KyleP Created
//
//--------------------------------------------------------------------------
class CXprPropertyRelation : public CXpr
{
public:
CXprPropertyRelation( PROPID pid,
ULONG relop,
CStorageVariant const & prval,
CRestriction * prstContentHelper );
CXprPropertyRelation( CXprPropertyRelation & propxpr );
virtual ~CXprPropertyRelation();
virtual CXpr * Clone();
virtual void SelectIndexing( CIndexStrategy & strategy );
virtual BOOL IsMatch( CRetriever & obj );
private:
CXprPropertyValue _xpval; // Gets value from filesystem
BOOL (* _relop) (PROPVARIANT const &,
PROPVARIANT const &); // Relational operator
CStorageVariant _cval; // Constant value
ULONG _rel; // Relation (used if type
// mismatch)
XPtr<CRestriction> _xrstContentHelper; // Content helper.
};
//+---------------------------------------------------------------------------
//
// Member: CXpr::CXpr, public
//
// Synopsis:
//
// Arguments: [type] -- type of expression
//
// History: 27-Sep-91 BartoszM Created.
// 23-Jun-92 MikeHew Added Weighting.
//
//----------------------------------------------------------------------------
CXpr::CXpr(NodeType type, ULONG ulWeight ) :
_type(type), _weight(ulWeight)
{
END_CONSTRUCTION( CXpr );
}
//+---------------------------------------------------------------------------
//
// Member: CNodeXpr::SetChild, public
//
// Synopsis: Set the child expression at a specific position.
//
// Arguments: [child] -- New child node.
// [iPos] -- Position of node.
//
// Requires: [iPos] is a valid index.
//
// History: 12-Dec-91 KyleP Created.
//
// Notes: The position of an expression within the node is not
// guaranteed to be constant over all operations on the node.
// The only safe way to use this function is after a call to
// GetChild.
//
//----------------------------------------------------------------------------
inline void CNodeXpr::SetChild ( CXpr* child, unsigned iPos )
{
Win4Assert ( iPos <= _cXpr );
_aXpr[iPos] = child;
}
//+---------------------------------------------------------------------------
//
// Member: CNodeXpr::GetChild, public
//
// Synopsis: Retrieves a child expression without removing it from the node.
//
// Arguments: [iPos] -- Position of expression to retrieve.
//
// Requires: [iPos] is a valid index.
//
// Returns: A pointer the the expression at [iPos].
//
// History: 12-Dec-91 KyleP Created.
//
// Notes: You are just 'borrowing' a node when retrieving it with
// this method. Do not delete the borrowed node!
//
//----------------------------------------------------------------------------
inline CXpr* CNodeXpr::GetChild ( unsigned iPos )
{
Win4Assert ( iPos <= _cXpr );
return _aXpr[iPos];
}
#ifdef DOCGEN
//+---------------------------------------------------------------------------
//
// Member: CXpr::NType, public
//
// Returns: Type type of this particular node (AND, CONTENT, etc.)
//
// History: 23-Sep-91 KyleP Created.
//
//----------------------------------------------------------------------------
NodeType CXpr::NType() const
{}
#endif /* DOCGEN */